A corpora



June 3, 1930. J. H. BoLLEs ET. AL 1,762,116

TRANSMI S S ION LOCK Filed April 2, 1928 Willi/Illa www Patented June 3, 1930 UNITED STATES PATENT OFFICE JULIUS H. BULLES, OF DETROIT, AND FRANK C. PEARSON, OF LANSING, MICHIGAN, AS- SIGNORS T GENERAL MOTORS CORPORATION, OF DETROIT, MICHIGAN, A. CORPORA- TION OF DELAWARE Application filed April 2,

This invention relates to anti-theft devices and more particularly to an arrangement for locking gear-shifting mechanism, such as commonly employed on motor vehicles,

against unauthorized manipulation.

One of the objects of the invention is to provide an improved transmission loch that will be simple in design, economical in maimfacture, convenient and easy to control, and

tamper-proof in use.

It is a further object of the invention to provide a lock for gear-shifting mechanisms that is automatically operated, coincidentally with the proper manipulation of a key-controlled switch governing the ignition system for an internal combustion engine.

Other objects and advantages will he apn parent from the following specification taken in connection with the accompanying drawings, in whieh- Fig. 1 is a side elevation of a transmission unit and ignition switch arranged in accordance with the present invention.

F ig. 2 is a sectional view taken on line 2w-2 of Fig. 1.

Fig. 3 is a sectional view taken on line of Fig. 2.

Fig. 4 is a sectional view taken on line Jf-f of Fie'. 5, showing a mmlitication.

Fig. 5 is a section on line .55 of Fig. 4:.

F ig. (j is an enlarged sectional view showing in detail the assembly of a holting element and its actuating wire or cable.

Referring to the drawings hv reference characters, the numeral 1 indicates a housing or casing for a selective siiding gear transmission. the gears of which are controlled by shifter forks 2 and 23 tixedly carried on a pair of sliding rods or shafts 4. and 5 mounted in spaced parallel reiation in the transmission cover 6. A lnanualiy operated shift lever 7, m-ounted for universal movement in the pedestal or dome 8 of the cover 6, is adapted upon proper manipulation to move either of the rods 4-5 to shift the transmission gearing and couple the driving shaft 9 and driven shaft 10 in certain speed ratios. In the neutral or inoperative position of the gear shifter rods 4 and 5 semispherical grooves or depressions 12 and 13,

TRANSMISSION LOCK 1928. Serial No. 266,650.

respectively, formed in their upper surfaces are in alignment with each other, and into these depressions extend a pair of spherical pawl elements or balls 14 and 15, which are adapted to move up and out of the grooves and ride on the top surfaces of the rods when the rods are shifted to and fro. In the upper portion of the transmission cover 6 is located a circular opening or bore 16 extending transversely or at right angles to the shifter rods, and in which is slidable a bolt element com-- prising a pair of integral plungcrs 17 and 18 joined by a neck portion 18 of reduced di` amcter and through which extends a fieXihle wire or cahle 19 ixedly secured thereto by a p lug 19 screw-threaded in the enlarged opening at the end of the holt element and having a tapered or conical end portion which cooperates with a similarlr shaped shoulder in the opening through the bolt to firmly clamp the bent over end of the wire. The wire 19 ieads through a fiexilole hose 20 to a distantly located easing 21 preferably mounted on the instrument panel 22 and which encloses the customary switch of the engine ignition system. A key 23, Within easy reach of the driver, controls a lock housed within the casing 21, which when opened closes the ignition circuit and pushes on the wire 19 to slide both plunger-s 1T and 18 to a position where no interference will he offered to the rise of the pawl elements 14 and 15 upward into the here 16, and when the mechanism is locked by the key, the ignition switch is opened and the plungers 17 and 18 are moved directly over the halls 14 and 15, as shown in Fig. 2, and hold such halls in the grooves 12 and 13, thereby locking the rods in neutral position.

In order to hold one of the rods against accidental movement when the other is moved from' its inoperative position, there is provided an interlock comprising a series of halls 24 located within a circular bore or opening 25 in the cover plate 6, and between the spaced rods. These balls are adapted to he shifted sidewise in the opening 25 and to extend within semi-spherical notches or grooves in the sides of the shifter rods, the combined width of the several balls being equal to the distance between the shifter rods,

plus the depth ot' one notch, whereby when one of the rods is moved the balls will be shifted toward the other roth one ot the endmost balls riding` on the surface ot the shifted rod and the ball at the other end of the series extending into the groove to lock the rod against movement.

ln the modilied eonstrlution illustrated in Fig. Je. the transmission rover 3l carries a pair ot shifter rods 32 and 33. and slidable in an openingr 3l therein are a pair olf' plunger ele-- ments l5 and 3G Iixed on the Wire 37, which plunger elements have loi-king engagement dirertl \Y Within grimves in the top surfaces ot the shit'ter rods when the same are in the neutral position.

ln this instaure the plunger elements are `separatelyY formed and independently secured on the flexible operatingr wire as distinguished from the integral type heretotore referred to, and the several ball elements employed with the eonstruetion previously described have been omitted.

It is to lie understood that the invention is not limited to the exact details shown, but that snel] modifications maybe made as come within the seope ol` the appel'ided claims.

Having thus described our invention.y we elaim l. ln eombination, a pair of independentl v slidahle ivorl; iin-formingl members arranged in parallel relation in the same horizontal plane an'l having depressions in their upper surliaees whirh are brought into alignment when both members are in inoperative position. a pair ot gravit@`- controlled pawl elements adapted to ride on said sui-tacos during movement ot the members and to drop into the depressions when the members are in the inoperative positions, and a pair ot' reciproeable plungei's movable in a horizontal plane to and l'rom a position in which the)v hold thi pan'l elements from raising out of said (lepre` ons thereby looking said members` against slidingl movement.

2. ln combination. a` plurality of shifter rods arranged in parallel relation in the sanne horizontal plane and a series of plungers, one for earh rod,y Agrouped and fixed with one another in sneressive alined relation for unison movement ransversely of said rods in a hor izontal plane spared from that oli' the rods, to lock all the rods against movement.

33. ln eomliinatioin a horizontally movable shalt having` a depression in its upper surtace. a gravit)v eontrolled pavvl adapted to ride on the upper surface of the shatt durinici shaft movement and to drop into said depression at a predetermined point in the range of sha lit movement, and a horizontally shittahle derire movable to overlie the pawl when in. the depression to engage and hold the pawl in the depression, thereby locking the shaft against movement.

4. In combination, a transmission housingr having a` plurality of spaced longitudinally extending' parallel openings therein, arranged in the same horizontal plane, and a single transversely extending horizontal opening spaced above the plane of the longitudinal openings, and vertical passageways between said longitudinal openings and the transverse opening. a shifter rod in each longitudinal opening` having a depression in its upper surface, a paivl in each vertical passage adapted by its weight to ride on the upper surface ot the adjacent shifter rod with its top portion extendingl into the transverse openingr when the paWl is out of the depression. and a plunger in the transverse opening movable over the series ot pawls when all are in the depressions to preclude their rising ont ot the depressions, and thereby lock the rods against shifting movement.

In testimony whereof We aix our signatures.

JULIUS H. BLLES. FRANK l. PEARSON. 

